Patent Literature 1 describes a solid-state image pickup device having a configuration of removing a random noise of a video signal. The solid-state image pickup device is provided with a pixel array, and an output circuit for reading out a video signal from the pixel array. The solid-state image pickup device includes a pixel array to which two output circuits are connected. The two video signals output from the two output circuits are subject to processing such as averaging, and noise is thereby removed from the video signal.
Patent Literature 2 describes an image pickup device capable of reducing the thickness of a device. The image pickup device is provided with a plurality of region sensors, and a plurality of microlenses for forming a subject image onto each of the region sensors. The subject image formed onto the region sensor is a whole image of the subject. The plurality of microlenses have respectively different focal lengths. When the image is generated, output from the region sensor onto which a subject image having an appropriate focal length is formed is used. Therefore, it becomes possible to eliminate a movement mechanism of a microlens for performing a focal adjustment, and it is thus possible to reduce the thickness of a device.
Patent Literature 3 describes an image input device capable of acquiring a high resolution image even when a distance between a subject and a microlens array is large. The image input device is provided with a plurality of configurations where a microlens and a light-receiving cell onto which a subject image corresponding to a microlens is formed are combined. A relative positional relationship between the microlens and the light-receiving cell differs for each combination. Therefore, even when the distance between the subject and the microlens is large, it is possible to improve the resolution of an image because a different subject image is formed onto each light-receiving cell.
Patent Literature 4 describes a system for acquiring a three-dimensional light field. This system is a three-dimensional display system which can be used for a television and a digital entertainment where three-dimensional light field data is needed.